Fuel injection pump



NOV. `6, 1951 5,' 0, JAKQBSEN v 2,573,792

FUEL INJECTION PUMP 5 Sheets-Sheet Filed ,neej 29, 1947 nimh! NA nl Nov.6, 1951 s. o. .JAKoBsEN l 2,573,792

v FUEL INJECTION PUMP v Filed Dec. 29, 1947 4 5 sheets-sheet 2Nov.'6,;l951 s. .,J;AKoBsE`N l f 2,573,792

l l J gI FUEL NJEcTIoN PUMP n Filed Dec. 29, 1947- i v v s sheets-sheets f rE-g.' 1n- Patented Nov. 6, 1951 UNITED 'STATES PATENTV oFFlcE A2.51am y FUELnmscrIoNPUMP Application December 29, 1947, Serial No.794,403

Norway August 24, 1946 Section 1, Public Law 690, August 8,1946

Patent expires August 24, 1966 V 7 Claims. (Cl. 123-139) The presentinvention relates to a fuel injection pump provided with one or morepumppistons, for the injection of fuel into a number of internalcombustion engine cylinders corresponding to the number of pump-pistons.It is the object oi the invention to provide a fuel'pump functioningreliably and more accurately and eectively than the pumps knownhitherto. It is another object of the invention to make the pump betteradjustable.l

The main feature of the invention is the fact that the fuel pump isprovided with a special, adjustable valve, located outside thepump-cylinder or -cylinders, the object of said valve being to controlthe operations of all the pumps. It is a further characteristic featureof the invention that the valve body, which has a cylindrical form, ispivotably Aand axially displaceable in a cylinder, the valve being madein such a way that, when rotating, it opens and shuts olf respectivelythe ducts carrying fuel to the various pump-cylinders, one after theother in succession, whereas said valve. when axially displaced, causesa change in the-quantity of fuel injected with every pressurev stroke ofthe pump-piston, said quantity of fuel controlling the rotation speed ofthe engine. It

running through the'pump, owing to a changev in the rotation speed ofthe engine, acts upon the valve body in such a way that it is displacedaxially in a manner dependent on the fuel pressure corresponding to therotation speed of the engine. Other characteristic features of theinvention are disclosed hereinafter.

The invention is, by way of embodiments, illustrated on the attacheddrawings.

Figure 1 shows an axial sectional view of an embodiment of the fuelpump; Fig. 2 is a partial axial sectional view of a reversing mechanism;Fig. 3 is a partial axial sectional view of a modied reversingmechanism; Fig. 4 is a top view of the embodiment sho'wn in Figure l;Fig. 5 is another axial sectional view of the embodiment shown in Fig. ltaken at the right angle to the section shown in Fig. 1 and seen fromright towards left; Fig. 6 is a cross sectional view of the fuel pumpalong the lines VI-VI in Fig. Fig. 'I is a cross sectional view of thevalve body along the line VII-VII in Fig. 5; Fig. 8 is a cross sectionalview of the valve body along line VIII-VIII in Fig. 5; Fig. 9 is adiagrammatical view of an arrangement for manual axial adjustment of thevalve body; and Fig. 10 is an axial sectional view of another embodimentof the fuelpump.

- The fuel pump. will be describedvaccording to the embodiments shown inFiguresl 1--8 incluslvely.V The various parts of lthe fuel pump.cylindersand channels are located in a pumphousing, consisting of acylindrical cylinder-block I. which, at its lower end, is providedjwitha lid 2, and at its upper end with a cap or sleeve 3 so as to form acyllndrically shaped cavityl I' between said cap 3 and thecylinder-block I. The lid 2 and the cap 3 are securedrto thecylinderblock I by means of. screw-boltsY (notshownl The cylinderfblock4I has. an axiaLLbox'irigj serving asa valve cylinder, inwhich provideda cylindrical valve-body, which isfaiiiif` ally displaceable. Saidvalve-bodyv is, inthe way described below, connected t0 u SDIldle I,driven by. the engine, said spindle beinglaxiallyv disposed' in relationto the valve-body and projectinginto the pump-housing through a centralboring 8 provided in the cap 3 insuch manner that the valve-body, whenthe engine is running, is set in rotation by the spindle, In thecylinder-block I, outside the valvefcylinder 5, are symmetricallyprovided a number of pumps, in a preferred embodiment six, consisting ofpump cylinders 9 disposed parallel to the valve cylinder, said pumpcylinders being provided with pump pistons I0 displaceable in thecylinders. Foreach engine cylinder there is provided one pump, the fuelbeing injected by the pumps into the respective cylinder from thelowe'.end of the pump cylinder through nipples II, which by means oftubings are connected with respective injection nozzles. f The drivingmechanism for the pump pistons I0 comprises a circular disc I2 providedin the cavity 4 under the cap 3, said disc having an axial boring andbeing threaded on to the spindle 'i and locked thereon by means of atransversal bolt I3. The upper face I4 of the disc is disposed at aright angle with the spindle, slidingly engaging the radial inside faceof the cap 3. The lower face I5 of the disc I2, on the other hand,defines a suitable angle with the direction of the spindle, and saidsloping face I5 engages slidingly a relatively thin annular disc I6,which is looselymounted on the spindle 1. The latter disc is intendedalways to have a sloping position, as a pin I1 inserted into the spindlewill prevent the higher part of the disc from coming down. The disc I6is made non-rotatable by means of a sliding member I9 provided in anaxial boring I8 in the cylinder-block I, the upper end of said slidingmember engaging a recess 26 in the edge of the disc I6 and abuttingagainst the lower face of the disc I2. The sliding member I9 is pressedin a vertical direction by a spring 2I provided in the cylinder I8. Thesliding member is also provided with an axial channel 22 having at itsupper end evacuation channels 23 in order to prevent the oil, being leftin the cylinder under the sliding member, from remaining there andthereby hampering the movements of the sliding member. Between theradial face of the cap 3 and the upper face of the disc I2 as well asbetween the lower face of the disc and the annular disc I6 are providedannular grooves containing balls 24 in order to reduce the frictionbetween the faces mentioned during the rotation.

During the rotation of the spindle 1 and the disc I2 the latter willslide on the disc I 6, whereby the latter will move in such a rockingway without taking part in the rotation, that'every part of said disc I6 will be in constant reciprocating motion axially, but with a diierentphase. In this way new edge portions of the disc I6 will always, oneafter the other in succession, be in the lowest position, so that thepistons I0, the upper ends of which abut against, or, respectively, areengaged by the lower faceof the disc I6, in succession will be presseddownwards in the pump cylinders without any sliding taking place betweenthe pistons and the disc I6. As soon as a piston has reached its lowestposition while the rotation of the spindle is going on, the piston isbrought back again to its upper position by means of a spring 25provided in the pump cylinder (as shown in Figure 1) or by means of areversing mechanism associated with the spindle. This mechanism may,similarly to the described mechanism for pushing the pistons downwards,consist of a sloping, nonrotatable annular disc 26, which slidinglyabuts against the upper sloping face of the disc 28, which is secured tothe spindle 1 by a bolt 21. The edge of the disc 26, as shown to theright in Figure 3, engages a groove 29 at the upper end of the piston,and as the disc 26, in the way already described, will be moving in arocking manner, the pistons will, each in succession, be forced upwardsinto their upper position. In Figure 2 the enforcement" reversingmechinism is shown, the disc 26 abutting under a head 30 provided at theupper end of the piston. As shown, the upper ends of the pistons aregiven a conical shape with a sloping` angle equal to the. slopingposition of the disc I6, in such a way that said disc, when being rockedup and down, will abut against, and roll on, part of the conical endfaces of the pistons. Thus a portion movement of thev pistons isavoided.

ln order to make an adjustment of the stroke of the pistons possible andadjustment screw 3| with safety nut 32 is provided in the cap 3, one foreach piston. The lower ends of these screws form abutments for thepiston-heads, so that the upper positions of the pistons may be adjustedat will.

Every pump-piston is in association with the valve cylinder 5 through achannel 33, and the fuel is sucked through this channel into the pumpcylinder 9 during the suction-stroke of the piston. The inlet openingsfrom the valve cylinder 5 to these channels are opened and shut ofirespectively, in the way described below, by the valve-body 6 during therotation of same. The fuel oil is, during the suction-stroke body mayhave.

of the pump pistons sucked into the fuel pump through the nipple 34 andthe axial channel 35 provided in an adjustment screw 36, arranged in acentral boring in the lid 2. The upper poriion 31 of said screwprojects, without touching the sides, somewhat into the lower end of anaxial boring 3B extending through the valvebody 6, and the upper end ofthe screw is rotatably abutting against the lower end of a rotatablebolt 39 axially displaceable in the boring 38. The upper end portion ofthe bolt 39 protrudes out of the valve-body 6 and extends into a boring40 provided in the lower end of the spindle 1. By means of the devicesdescribed below the bolt 39 serves for coupling together the spindle 1and the valve-body 6. The channel 35 provided in the screw 36 isassociated with an axial channel 4I in the lower end of the bolt 39, andthrough a transversal boring 42 provided in the bolt the channel 4I isassociated with a hole 43 in the wall of the valve, said hole opening upinto a groove 44 provided in the outer Wall of the valve. This groove 44extends over an angle of about and has such an axial position, that .theends of the channels 33, which open up into the valve cylinder, alwaysare located between the planes through the upper and lower end of thegroove 44, whatever axial position the valve- When the channels 33during the rotation of the valve-body are in a position just oppositethe groove 44, the fuel will be sucked into the pump cylinders duringthe suction-stroke of the pump piston, the fuel flowing upwards throughthe nipple 34 and the channels 35 and 4I and thence through the boring42 and the hole 43 into the suction-groove 44, whence it is suckedthrough the channels 33 into the pump cylinder. For each piston thissuction takes place as long as the `channel 33 is in association withthe suction-groove, that is to say: in the course of one half rotationof the valve-body.

Besides having the suction-groove 44 the valvebody 6 is provided withtwo pressure-grooves 45 and 46, lying on a level with thesuction-groove, but separated from this suction-groove by means of axialpartitions 41 and 48 respectively, the outer faces of which are alignedwith the surface of the valve-body. The two pressure-grooves areseparated from each other by a portion 49 of the valve-body, saidportion not being provided with any groove, and which therefore duringthe rotation is tightly engaging the wall of the valvecylinder. Thisportion 49 is tapered downwardly, having suitably curved limiting edges50 and 5I provided symmetrically on both sides of an axial plane. It isnecessary that the limiting edges are symmetrically arranged in orderthat the fuel pump can be used whatever direction the engine may rotate.

The pressure-grooves 45 and 46 are, through holes 52, 53 and axialchannels 54 and 55, respectively, in association with a compressionchamber 56 between the lid 2 and the lower end of the valve-body 6, andthe suction-groove 44 is, through corresponding holes and axial channels51 and 58, associated with the boring 40 provided in the lower end ofthe spindle 1. 'I'he upper end of said boring 40 is, through a channel59 in the disc I2, associated with the cavity 4 in the cap 3. In saidchannel 59 is provided a ball 60 serving as a valve-body, said ballbeing on account of the centrifugal power pressed against the inletopening from the cavity 4 into the channel 59, the pressure increasingwith the increased rotation speed of the engine.

The compression chamber 66 is, through channels 6| and `62, associatedwith the cavity 4. Between said channels is inserted a throttling valvey consisting ofv a cylinder 63 rotatably provided in a boring in thecylinder-block I, said cylinder having an axial boring 64. The cylindermay be rotated by means of a handle 65 provided at the end of avalve-rod 66 associated with the cylinder. Said valve-rod is rotatablyhoused in a housing 61, which is secured to the cylinder-block i by thescrew 68. The valve cylinder is suitably acted upon by a spring 69. Thechannel 6l is associated with the open end of the boring I64 of thevalve cylinder, and the channel 62 is associated with said boringthrough a hole 10 in the cylinder wall. This hole has a form suitablefor the adjusting or throttling of the circulation area of the valvemore or less, at will, and eventually, for shutting oir the valvecompletely, said adjustments being effected by turning the valve-rod 66.

In the two ends of the spindle 1 and the valvebody 6 facing each otherborings are provided,

4into which is inserted a compression spring li,

which tends to push the valve-body in a downward direction. However, theoil-pressure developed in the compression chamber 56 will exert apressure on the valve-body in the upwards direction against said spring,and thus the axial position of the valve-body will depend on the extentof the oil-pressure. The tension of the spring must be adjusted in sucha way that the springtension, by increased oil-pressure, will increasemore rapidly than the oil-pressure itself, in such manner that a certainaxial position of the valvebody always corresponds to each amount ofoilpressure. y

The fuel pump here described makes possible an automatic adjustment ofthe rotation speed of the engine according to a certain valuepredetermined at will. The operations of the fuel pump are as follows:`

During the rotation of the engine, and thereby also during that of thevalve-body, said engine parts going at a certain speed which is to bekept unchanged, the valve-body will take a certain axial position,whereby the channels 33 wil1 be shut on" from or, alternately,associated with the suction-groove 44 and the pressure-grooves 45 and46. Hereafter, only the operations of one of the pumps will be discussedbecause the opera--v tions of all the pumps, each in succession, areidentical. When one of the channels 33 is in association with thesuction-groove 44 during the suction-stroke of the pump piston, the oil,as it is already pointed out, will be sucked upwards through thechannels 35 and 4l into the suctiongrooveand thence into the pumpcylinder below the piston. When the piston has reached its top position,the valve-body will have rotatedso far that the opening of the channel33 has reached the end of the suction-groove. Upon further rotation ofthe valve-body the channel 33 will pass by one of the partitions betweenthe suctiongroove and one of the pressure-grooves, for instance thepartition indicated at 48 in Figure 1, whereupon said channel will beassociated with one of the pressure-grooves 46. The piston now hasstarted its pressure-stroke, whereby the oil situated below the pistonwill be pressed into the pressure-groove 46. Thence the oil is pressedthrough the channel 6I, the throttling valve 63, 64 and the channel 62into the cavity 4, whence the oil is pressed by the valve-ball 60through the channel 59 into the boring 40 provided in the spindle 1 andfurther through the channels 5l and @il down into the suction-groove 44.During the operation of the fuel pump all the said channels andenclosures will be lled with oil, and a constant Iiow of oil will becirculating through the throttle valve 63, 64. Upon further rotation ofthe valve-body the opening of the channel 33 will pass the limiting edge:5| of the portion 49 and will remain completely shut off as longas thepassing of this portion takes place. As long as this is the case, theoil cannot escape .through said pressure channels, whereby the oilpressure in the pump cylinder will increase to such a degree that theoil will be injected into the engine cylinder. This injection willcontinue until the opposite limiting edge 50 of the portion 49 hasreached the opening of the channel 33, the length of the injectionperiod thus being dependent upon the axial position of the valve-bodyrelatively to the opening of the channel 33.

After the termination of the injection period, the pump piston willcontinue its pressure-stroke, and now the opening of the channel 33 isin association with the second pressure-groove 45. Part oi the oil willnow, as previously described,- be pressed through the channel 54 downinto the compression chamber 56, thus maintaining the oil circulationthrough the throttling valve 63, 66.

In describing the functioning of the fuel pump a constant rotation speedof the engine and a certain axial position of the valve body without anydisplacement taking place has been assumed. In case the speed of theengine, for one reason or other, is changed, for instance increased, thespeed of the pump piston will increase, and thus a greater quantity ofoil will be pressed down into the compression chamber 56 and furtherthrough the system of pressure channels per unit of time. Consequentlythe oil will circulate more quickly through this channel system, wherebythe circulation resistance will be increased. Owing to this fact the oilpressure in the compression chamber 56 will increase to such a degreethat the valve-body will be pressed upwardly against the tension of thespring 1i. However, as the tension of the spring will increase morerapidly than the oil pressure, the valve-body wi`l, after being suitablydisplaced, take another axial balanced position. In this new position ofthe valvebody the opening of the channel 33 will be closer to the lowerpoint of the valve portion 49, this causing a shortening of theinjection period. Consequently, a smaller quantity of oil will bepressed into the engine cylinder per unit of time. At the same time, acorrespondingly greater quantity of oil will ybe pressed through thepressure chamber system, this again causing a further increase of thepressure in the compression chamber 56. On account of the reducedinjection of oil per unit of time, the rotation speed of the engine nowwill decrease, whereby the number of pump piston strokes per unit oftime Will decrease, this fact effecting a decrease of speed in thecompression chamber. As a result of all this, the pressure in thecompression chamber 56 will decrease, so that the spring 'll will bringthe valve back into its original position. In the case of a reduction ofengine speed, the adjustment, obviously, will be carried out in themanner already described, only in the reversed order.

As already stated the rotation speed of the engine is .dependent uponthe circulation resistance in the pressure chamber system. By means ofthe automatic control the circulation resistance is changed through avariation of the* circulation speed in the pressure chamber system. Said.topmost position. In this way the opening of the channel 33 will not beclosed during the rota- 1tion of the valve, so that there will be nofuel injected into the engine cylinder.

The spindle 1 is coupled together with the valve-body 6 by means oi' theaxial bolt 39, which in its upper end is locked to the spindle by meansof the transversal split-pin 21. 'Ihe bolt 361scoupled together with thevalve-body 6 by means of a ball 12 engaging an axially provided groove13 in the inner wall of the valve-body, said bolt 12, in addition,engaging a transversal groove 14, which extends over 180 Yin the bolt39. Thus said bolt 39 may be displaced axially relatively to thevalve-body 6 as well as to the spindle 1. The upper end oi' the bolt 39is actuated by a compression spring 15, whereas the lower end of same isrotatably abutting against the upper end of the top portion 31'of theadjustment screw 36 in such a way that the bolt may be displaced axiallyby adjusting the screw 36. This axial displacement of the bolt 39changes the angular position of the valve-body relatively to the'spindle 1. 'I'his is obtained by the split-pin 21 engaging a downwardlytapering recess 16 provided in the upper end of the bolt 39. When thebolt by means of the screw 36 is displaced vertically, the split-pin 21will assume during the rotation different angular positions relativelyto the bolt according to its higher or lower position in the recess 16.Said recess isV located symmetrically relatively to the portion 49 ofthe valve-body controlling the injection.

When the direction of the engine rotation is to be changed, thevalve-body has to be rotated 180 relatively to the spindle 1, which ismade possible by the fact that the ball 12, by changing the direction ofthe engine rotation, moves 180 along the groove 14 provided in the bolt39.

In case the oil pressure developed in the pressure channel Asystemduring the pressure-stroke should rise too rapidly, the oil will bepressed through the channels 51 and 58 into the suction.

groove 44, and thence return to the oil-tank through the channels 4| and35. Further safety is obtained by the fact that the oil, in the case ofan abnormally high pressure in the compression chamber 56, will bedriven upwards around the top portion 31 of the screw 36 and push thebolt 39 in an upward direction, whereby the oil from the compressionchamber will be forced directly into the channel 35 and thence llow backto the oil-tank.

The fuel pump may also be adapted for manual adjustment of the rotationspeed of the engine. For this purpose, a manually operatedadjustment-rod 11 may be provided in the cylinderblock l. as shown,diagrammatically, in Figure 7, the inner end of said adjustment-rod 11being provided with an eccentrical pin 16 engaging an annular groove inthe valve-body 6. By rotating the rod 11 the pin 18 will cause an axialdisplacement of the valve-body into the position corresponding to thedesired rotation speed.

A modified embodiment of the fuel pump is shown in Figure l0. Accordingto this embodiment a change may be made in the angular position of therocking, non-rotatable disc 19 moving the pump pistons, said changebeing carried out in such a way that the piston strokes of all the Pumpsmay be controlled by simply adjusting one nut 86. The lower edge of saidnut is, by a split-pin 6I, associated with an annular disc 62 slidinglyabutting against another annular disc 63. Both said annular discs arelocated in a rotatable cylinder 84, the lower annular edge of which istapered. Against this sloping edge the annular disc 65, which isslidingly provided on the rocking disc 19, is abutting, at least at thelowest point 66 of said sloping edge, in such a way that both said discsmay be swung somewhat about this point into different sloping positions.Between the annular discs 83 and 85, on

the side of the spindle 1 which is diametrically opposite the said point86, is provided a transversal bolt 61, the ends of which engage recessesn 66 in the edge portion of the cylinder 64. The

bolt 61 forms an abutment for the top-most edge portion of the annulardisc 65, the annular disc 1 9 and 65 being kept in an up-turned positionby the pump pistons acted upon the springs 25. When the nut is turnedthe bolt 81 will be displaced vertically so that the sloping position ofthe annular discs 19 and 85 is changed. The annular disc 19 is slidinglyresting upon the ends of a split-pin inserted through the spindle 1,said split-pin sliding along the disc during the rocking motion of same.

According to the embodiment shown in Figure l the split-pin 21 may, byinaccurate adjustment, abut only against one side of the recess 16 andthereby cause a pressure side-ways on the bolt 39. In order to avoidthis, a wedge-shaped. downwardly tapering coupling-member 9| has,according to Figure 8, been mounted upon the bolt 21, said memberprotruding down into the recess. The wedge-shaped member being rotatableon the split-pin, it will, when the bolt 39 is turned `round always takesuch a position that it will be in contact with both sides of therecess.

The axially extending groove 13 in the inner wall of the valve-body is,according to Figure 10, slightly wedge-shaped longitudinally, in such away that both edges of the groove suitably form equal angles relativelyto the axial direction. During the rotation the ball 12 will abutagainst one or the other ofthe two edges of the groove, dependent uponthe direction of rotation, and when the valve-body during the adjustmentoperations is displaced axially, it will, as a consequence, be turnedsimultaneously.

When the direction of rotation is changed, the spring 1I, when it isused as shown in Figures 1 and 5, on account of its friction against thespindle 1 and the valve-body 6, may couple together these last mentionedmembers with such a great force, that the valve-body does not turn therelatively to the spindle, made possible by the ball 12 rolling in thegroove 14 provided in the bolt 39, all this causing an incorrectposition. In order to avoid this, the spring 1i, according to theembodiment shown in Figure l0, is located in the end of the valve-bodyfacing in the opposite direction of the spindle 1, the outer end of saidspring engaging a rotatable disc 92, whereby said spring will not beable to couple together the valve-body and the spindle. In this case thevalve-body must have an inversed position relativelyto its positionshown in Figures 1 and 5, and the oil compression chamber 56 will belocated between the upperend of the valvebody and the spindle. While theoperations are identical with those already described. the variouscirculation channels are not shown in Figure 10. In this embodiment ofthe fuel pump, these channels are not associated with the cavity 4,which only contains lubricating oil. Fuel-oil, which, on account ofleakage, is driven up surrounding the pistons, is absorbed by grooves 93provided in the piston-cylinders, and is thence, through channels 94,brought back to the circulation channels. y

In order to avoid leakiness, which may arise because the pistons areunevenly worn, the lower portions of said pistons may, as shown inFigure l0, be divided into shorter pieces 95, which are loosely abuttedagainst each other.

In the pump construction disclosed here the lower ends of the pistonsprings abut (against the nipples Il, whereby thesprings arebasilydismountable upon the screwing off thefyi'pples.

The construction may vary in details/'from the one here described.Furthermore, the pumps and the valves may have a reciprocal positiondifferent from the one shown on the drawings.

The pumps may for instance be located in the same plane and the valvemay have a position below and transversely to the pumps in the planethrough the latter.

I claim: I

1. An oil admission valve for fuel pumps comprising in combination acylindrical valve housing; a cylindrical valve chamber within saidcylindrical valve housing; a rotatable valve `body arranged within saidcylindrical valve chamber slidably in axial direction; at least one oilconduit reaching from a point of the cylindrical surface of said valvechamber to the fuel pump to which oil is to be supplied; a recess in thesurface of said rotatable valve body arranged so as to communicateduring part of each revolution of said valve body with said fuelconduit; means combined with said recess for varying the length ofcommunication of said recess with said fuel conduit depending upon theaxial position of said rotatable valve body; means arranged within saidvalve body for admitting oil into said recess during rotation of saidvalve body; means for rotating said valve body; an oil pressure chamberarranged at onel end of said valve body so that oil injected into saidchamber under pressure is adaptedto move said valve body in axialdirection; rst conduit means within said valve body adapted to connectduring part of each revolution of said fuel conduit with said pressurechamber; second conduit means within said valve housing and said valvebody connecting said pressure chamber permanently with said recess insaid valve body; and means for adjusting the flow of oil through saidsecond conduit means.

2, An oil admission valve for fuel pumps cornprising in combination acylindrical valve housing; a cylindrical valve chamber within saidcylindrical valve housing; a rotatable valve body arranged within saidcylindrical valve chamber slidably in axial direction; at least one oilconduit reaching from a point of the cylindrical surface of said valvechamber to the fuel pump to which oil is to be supplied; a recess in thesurface of said rotatable valve body arranged so as to communicateduring part of each revolution of said valve body with said fuelconduit; means combined with said recess for varying the length ofcommunication of said recess with said fuel conduit depending upon theaxial position of said rotatable valve body; means arranged within saidvalve body for admitting oil into said recess during rotation of saidvalve body; means for rotating said valve body; an oil pressure chamberarranged at one end of said valve body so that oil injected into saidchamber under pressure is adapted to move said valve body in axialdirection; first conduit means within said valve body adapted to connectduring part of each revolution said fuel conduit with said pressurechamber; second conduit means within said valve housing and said valvebody connecting said pressure chamber permanently with said recess insaid valve body; means for adjusting the ow of oil through said secondconduit means; and spring means permanently tending to move said valvebody within said valve chamber against the pressure exerted by the oilwithin said oil pressure chamber.

3. An oil admission valve for fuel pumps comprising in combination acylindrical valve housing; a cylindrical valve chamber within saidcylindrical valve housing; a rotatable valve body arranged within saidcylindrical valve chamber slidably in axial direction; at least one oilconduit reaching from a point of the cylindricalI surface of said valvechamber to the fuel 'pump' to which oil is to be supplied; a recess inthe surface of said rotatable valve body arranged so as pressure isadapted to move said valve body in axial direction;'iirst conduit meanswithin said valve body adapted to connect during part of each revolutionsaid fuel conduit withsaid pressure chamber; second conduit means withinsaid valve housing and said valve body connecting said pressure vchamberpermanently with said recess in saidpvalve body; means for adjusting theflow offoil through said second conduit means; shaft means for rotatingsaid cylindrical valve body; and connecting means for connecting saidshaft means'with said cylindrical valve body so as to automaticallychange the angular position of said cylmdrical valve body relative tosaid shaft means when said cylindrical valve body is moved by oilinjected into said oil pressure chamber in axial direction.

4. An oil admission valve for fuel pumps comprising in combination acylindrical valve housing; a cylindrical valve chamber within saidcylindrical valve housing; a rotatable valve body arranged Within saidcylindrical valve chamber slidably in axial direction; at least one oilconduit reaching from a point of the cylindrical surface of said valvechamber to the fuel pump to which oil isto be supplied; a recess in thesurface of said rotatable valve body arranged so asto communicate duringpart of each revolution of said valve body with said fuel conduit; meanscombined with said recess for varying the length of communication ofsaid recess with said fuel conduit depending upon the axial position ofsaid rotatable valve body; means arranged within said valve body foradmitting oil into said recess during rotation of said valve body; anoil pressure chamber arranged at one end of said valve body so that oilinjected into said chamber under pressure is adapted to move said valvebody in axial direction; rst conduit means within said valve bodyadapted to connect during part of each revolution of said fuel conduitwith said pressure chamber; second conduit means within said valvehousing and said valve body connecting said pressure chamber permanentlywith said recess in said valve body; means for adjusting the flow of oilthrough said-second conduit means; shaft meansfor rotating saidcylindrical valve body: connecting means for connecting said shaft meanswith said cylindrical valve body so as to automatically change theangular position of said cylindrical valve body relative to said shaftmeans when said cylindrical valve body is moved by oil injected intosaid oil pressure chamber in axial direction; and spring meanspermanently tending to move said valve body within said valve chamberagainst the pressure exerted by the oil within said oil pressurechamber.

5. A fuel pump comprising in combination a pump cylinder; a pump pistonarranged slidably within said pump cylinder; driving shaft means;operating means driven by said driving shaft means for periodicallymoving said pump piston from suction position into compressing position;moving means for periodically moving said pump piston back fromcompressing position into suction position; a cylindrical valve housing;a cylindrical valve chamber within said cylindrical valve housing; arotatable valve body arranged within said cylindrical valve chamberslidably in axial direction; an oil conduit connecting a point of thecylindrical surface of the valve chamber with the space within said pumpcylinder; a suction recess in the surface of said rotatable valve bodyarranged so as to communicate during part of each revolution of saidvalve body with vsaid fuel conduit; a pressure recess in the surface ofsaid rotatable valve bodyl arranged so as to communicate during anotherpart of each revolution of said valve body with said fuel conduit;connecting means between said driving shaft means and said valve bodyfor rotating the latter in such a manner that said suction recesscommunicates with said oil conduit while said moving means move saidpump piston from compressing position into suction position and saidpressure recess communicates with said oil conduit while said operatingmeans driven by said driving shaft means move said pump piston fromsuction position into compressing position; an oil pressure chamberarranged at one end of said valve body so that oil forced into saidchamber under pressure is adapted to move said valve body in axialdirection; first conduit means within said valve body connecting saidpressure recess with said oil pressure chamber; second conduit meanswithin said valve housing and said valve body connecting said pressurechamber permanently with said suction recess in said valve body; andmeans arranged in said valve housing for adjusting the flow of oilthrough said second conduit means.

6. A fuel pump comprising in combination a pump cylinder; a pump pistonarranged slidably within said pump cylinder; driving shaft means;operating means driven by said driving shaft means for periodicallymoving said pump piston from suction position into compressing position;moving means for periodically moving said pump piston back fromcompressing position into suction position; a cylindrical valve housing;a cylindrical valve chamber within said cylindrical valve saidcylindrical valve chamber slidably in axial direction; an oil conduitconnecting a point of the cylindrical surface of the valve chamber withthe space within said pump cylinder; a suction recess in the surface ofsaid rotatable valve body arranged so as to communicate during part ofeach revolution of said valve body with said fuel conduit; apressurerecess in the surface of said rotatable valve body arranged soas to communicate during another part of each revolution of said valvebody with said fuel conduit; connecting means between said driving shaftmeans and said valve body for rotating the latter in such a manner thatsaid suction recess communicates with said oil conduit while said movingmeans move said pump piston from compressing position into suctionposition and said pressure recess communicates with said oil conduitwhile said operating means driven by said driving shaft means move saidpump piston from suction position into compressing position; an oilpressure chamber arranged at one end of said valve body so that oilforced into said chamber under pressure is adapted to move said valvebody in axial direction; first conduit means within said valve bodyconnecting said pressure recess with said oil pressure chamber; secondconduit means within said valve housing and said valve body connectingsaid pressure chamber permanently with said suction recess in said valvebody; means arranged in said valve housing for adjusting the flow of oilthrough said second conduit means; and spring means permanently tendingto move said valve body against the direction of pressure exerted by oilin said pressure chamber.

7. A fuel pump comprising in combination a pump cylinder; a pump pistonarranged slidably within said pump cylinder; driving shaft means;operating means driven by said driving shaft means for periodicallymoving said pump piston from suction position into compressing positionand back; a cylindrical valve housing; a cylindrical valve chamberwithin said cylindrical valve housing; a rotatable valve body arrangedwithin said cylindrical valve chamber slidably in axial direction; anoil conduit connecting a, point of the cylindrical surface of the valvechamber with the space within said pump cylinder; a suction recess inthe surface of said rotatable valve body arranged so as to communicateduring part of each revolution of said valve body with said fuelconduit; a pressure recess in the surface of said rotatable valve bodyarranged so as to communicate during another part of each revolution ofsaid valve body with said fuel conduit; connecting means between saiddriving shaft means and said valve body for driving the latter in such amanner that said suction recess communicates with said conduit whilesaid operating means move said pump piston from compressing into suctionposition and said pressure recess communicates with said oil conduitwhile said operating means move said pump piston from suction positioninto compressing position; an oil pressure chamber arranged at one endof said valve body so that oil forced into said chamber under pressureis adapted to move said valve body in axial direction; first conduitmeans within said valve body connecting said pressure recess with saidoil pressure chamber; second conduit means within said valve housing andsaid valve body connecting saidpressure chamber permanently with saidsuction recess in said valve body; means arranged in said valve housingfor adjusting the housing; a rotatable valve body arranged within flowof oil through said second conduit means;

, 13V and adjusting means forming part of said connecting means betweensaid driving shaft means and said valve body for automatically changingthe angular position of said valve body relative to said driving shaftmeans during rotation of v the same when said valve body is moved inaxial direction by pressure of oil forced into said oil pressurechamber.

' SVEND OLDER JAKOBSEN.

REFERENCES CITED The following references are of record in the le oftnis patent:

Number Number UNITED STATES PATENTS Name Date Hoifer Dec. 9, 1941 AmeryAug. 4, 1942 Truxell, Jr 7.. Sept. 5, 1944 FOREIGN PATENTS Country DateGreat Britain Dec. 21, 1943 Germany Mar. 15, 1934

